Plywood panel



Oct.ll,1938. RAMULLER I '2,133,10s

PLYWOOD PANEL Filed Jan. 26, 1938 Patented Oct. 11,1938

I PLIWOOD PANEL Robert A. Muller. Wellesley, Mass assignor to Atlas Plywood Corporation, Boston, Mass a corporation ot'Massaohnsetts Application James, 193a, Serial Names This invention relates to plywood sheets .and

to methods of making products 01 this character for special purposes. The commercial methods of producing Ply.-

wood are such that there are fairly definite lim its to the sizes of the sheets of plywood which can be manuiactured economically. For most purposes the dimensions or these sheets are am pic, but occasionally situations arise which ,call 3 for sheets oi considerably larger sizes. A typical instance is in the crating of automobiles and machines for foreign shipme t. While such sheets or panels can be produced by obtaining special equipment to accommodate these larger sizes, the expenditure involved is not warranted by the relatively limited demand for them. i

The present invention deals with the problem presented by these conditions. It aims to devise a plywood sheet structure and a method of g joining plywood sheets with a view to producing exceptionally large sheets or panels while avoiding the necessity for using expensive special equipment.

The nature of the invention will be readily understood from the following description when read in connection with the accompanying drawing. and the novel features will be particularly pointed out in the appended claims.

' In the drawing,

Figure 1 is aperspective view of a portion of a plywood sheet embodying the present invention;

Fig. 2 is a vertical, sectional view approximately on the line 1-2, Fig; 1; and

Fig. 3 is a disassembled per p ctive view of the invention. I

'- The construction shown in the drawing comprises two'sheets or sections 2 and 3, respectively, of plywood which may be composed of any desired number oi plies. These sheets may be made up in standard dimensions and of the usual constructions, the grain in adjacent plies running at right angles to each other. The margins of these two plywood sheets are reduced in thlcmess to-substantiallyzone-hali that of the main portions of the sheets,-and these relatively thin marginal strips are overlapped upon each other, as clearly illustrated. For convenience in manufacture, the sheets may be initially produced in the usual manner, and the thin marginal strips subsequently are formed by rlmning these portions of the sheets through a scarling or planing machine whichremoves the surplus material and forms substantially smooth flat 5 surfaces on the area from which the stock has (cl. 2H1) been taken away.

abstainmm shoulde'rs, such as those'shown at a vaudib', are

- formed at the 'junction of the reduced margin with the main body oi the sheet; One-0r both of these marginal areas next is coated "with-an 5 "adhesive" cand, while such coating-is still moist and.tacky, the two margins are overlapped; one upon the other; in the relationship shown'swith the edge of each sheet abutte against the; shoulder of the other sheet. wi'th e sheets-held m in this relationship a series of hi alliofastenr ers are driven throughthe'- overlapped areas to secure them firmly together. after which-the; sheets are stacked in racks,"or any other suitablev manner, while the adhesive Prefer- 13 ably the fastening of the sheets is accomplished .by driving two rows of staples 4 and 5 along-the joints between the edges of the marginal strips and'the shoulders against which they abut, the staples straddling the joints and being clinched at the opposite side of the composite sheet. A multiplicity oi other staples, such-as those shown at 6", are driven through both-oi the overlapped stripsand clinched, the staples being either arranged in a row about midway between the two rows of staples 4 and 5,.or else distribued inany other manner necessary to cooperate with the latter in mechanically securing the entire areas of both sheets together. Naturallythe distribution of these staples and their spacing from each 39 other willdepend upon the requirements oi indlvidual situations.

The construction above described produces a composite sheet composed of the sections 2 and 3 with the overlapped joint madein themanner just mentioned. It has been found in practice. that this jointis practically as strong as a cor I responding section of either of the main sheets 2 or 3. The overlapped areas, however, should.

be ample to give the desired strength and rigidi-r ty, a typical width of each of the reducedstrips being'from three inches to live inches. The fact I that the staples straddle the edgesof thestrips which abut against the'shoulders a and b is important in contributingto the strength-oi the 5 union between the sheets'.-

'An important advantage of this process is that by assembling the sheets in the manner above described while the'adhesive between the overlapped areas is still soft and tacky, and then 50 driving and clinching the staples'or other iasteners, ample pressure can be applied by them to the glued joint to'hold the parts rl8ld1 in their final positions while'the glue sets. Thus. the necessity for compressing, the joined areas of -manufacturing expense for the reason that it avoids the necessity of using special equipment not customarily employed in a plywood plant,

and it reduces the handling expense which would be involved if it were necessary to use a plywood press.

The common "hardwood plywood sheets or panels are customarily made in sizes up to 4x '7 feet. By joining these or smaller panels in the manner above described, it is entirely feasible to produce very much larger sheets, and to accomplish this result very ecohomically.

In crating machines, automobiles, andthe like, for foreign shipment, it is often desirable to use a plywood which has been waterproofed. These sheets can be united in the manner above de-- scribed and the joint can be made waterproof by using a glue or cementwhich is either waterproof or not, as desired, but which, in any event, is compatible with the material used in waterproofing the board.

While I have herein shown and described a typical embodiment of my invention, it will be understood that minor departures may be made from this disclosure within the spirit and scope of the invention.

Having thus described my invention, what I desire to claim as new is:

lcAn article of the character described, comprising two plywood sheets, each provided with a marginal strip of substantially uniform thickness overlapped upon a similar margin of the other sheet, both of said margins being of reduced thickness compared with that of the adjacent portions of the sheet, and the extreme edge of each of said reduced strips being abutted against a shoulder on the other sheet formed at the junction of said reduced strip with the body of the sheet, and rows of staples straddling the respective joints between each of said shoulders and the adjacent edge of the other sheet, said staples being clinched upon the faces of said sheets opposite to said respective Joints.

2. An article of the character described, comprising two plywood sheets; each having a marginal stripthereof of approximately one-half the thickness of the main body of the sheet, said strips being of great width in proportion to their thickness and each being overlapped upon the other, with its edge 'abutted against a shoulder formed at the junction of the reduced margin with the main body of the other sheet, whereby a joint is formed between each of said shoulders and the edge abutting against it, a row of staples straddling each of said joints, and clinched upon the opposite sides of the respective sheets, and a plurality of additional staples driven through the overlapped portions of said strips and securing said strips together in face to face relationship.

3. An article of the character described, comprising two plywood sheets, each provided with a marginal strip of substantially uniform thickness overlapped upon a similar margin of the other sheet, both of said margins being of reduced thickness compared with that of the adjacent portions of the sheet, and the extreme edge of each of said reduced strips being abutted against a shoulder on the other sheet formed at the junction of said reduced strip with the body of'the sheet, rows of staples straddling the respective joints between each of said shoulders and the adjacent edge of the other sheet, said staples being clinched upon the faces of said'sheets opposite to said joints, and a coating of adhesive between the marginal strips.

ROBERT A. MULLER. 

